Herman was an Indonesian who killed a total of seven people and wounded seven others in two rampage attacks, the first occurring in Kuala Kapuas, Kapuas Regency in November 1922, and the second on a ship near Banjarmasin, Dutch East Indies in December the same year.[1]

During the first attack Herman, a Christian Dayak, killed six people and wounded two others with a spear and afterwards escaped, but he was eventually arrested by police.[2][3]

In December 1922 he was to be transferred to Banjarmasin for his mental examination, but while travelling on the S.S. Alting he grabbed a klewang from one of his two guards, and after leaving both of them wounded, killed one passenger, and injured three others, two of them seriously.[4][5]

In January 1923 he was found to be insane and later transferred to a mental institution in Java.[6][7]